I'm a Nerd

Whenever I get my car serviced, I write it down. I also record the mileage, because that can be important too. I happened to do this in Excel, so yesterday I was curious...what if I plotted the mileage of my car over time? Turns out it's pretty linear over the nearly 3 years that I've owned my car. In fact, it's kind of surprising how the linear regression lines up to the data. That is probably strongly influenced by the fact I'm only sampling every couple months so it ends up being dominated by my daily commute to work. I haven't really changed my commute over this time period, so I suppose I shouldn't be very surprised I drive about the same amount each day throughout the year.

Actually, you can see one big aberration that causes the linear regression to overestimate most data points - I went on an ~3,000 road trip over Christmas/New Year's last year. It doesn't make a huge impact on the average, about 2 miles per day it seems like.

Since I purchased my car, it appears that I drive 41.2 miles per day. This is obviously skewed by that road trip and a trip to Ottawa last summer; the data also shows that over periods without a long road trip I trend closer to 29 miles per day. Since I drive a pretty fuel efficient car, that's average Marylander uses like 415 gallons per year (2004 data). Some math tells me that I'm driving almost exactly 15,000 miles per year. History tells me that 32 mpg is a reasonable average for my car. That says that my car is using 470 gallons of gas per year. I could argue that for all of the long road trips (>150 miles round trip) that I've taken, I've had passengers, so they aren't all my gallons, but that's splitting hairs I guess. Wow, that puts me at the US average (~464 gallons per year (also 2004 data)).

This discovery really concerns me because I like the environment; that's why I bought a fuel efficient car! I'm going to have to try harder not to drive on the weekends (since I can't really control my need to drive to and from work). Now I'm sad, I had thought that I used less than the average amount of gasoline for an American. Turns out I'm part of the problem after all...

Some further research shows that I pay ~$86 in federal and >$100 in state taxes each year (it would be $110/year if I bought all of my gas in Maryland).

I still feel much worse about all my gasoline consumption than I do about finding out I pay an additional $200/year in taxes...and by now you know how I feel about paying taxes.